Question About Coefficient of Thermal Expansion

Low is presumably better unless you are making a nano-temperature sensor!
Del

i have prepared 5 samples, 4 of w/c is filled, and the other one is pure polymer as a reference, and the vaules ranges from 67-130um/m*C, the trend is increasing from pure to filled one. Sir Del and Sir CSM Engineer do you know any applications for this values of CTE? or anyone reading this post,

THANKS again!

Sure, like Del says, nano scale temperature indicators; either as temperature indicators or temperature switches. Perhaps if you can arrange a nice lattice structure, you can create a temperature dependant venting membrane. I don't know; as an engineer, I'm much better at starting with a problem and finding a solution. Having a solution and then trying to find the problem always seems much harder to me.

Great!, people here are the best. sharing knowledges through the net. im glad that i joined here. thanks everyone!

Just remember to list us on the patents!

Your nano fix is going the wrong way! This is likely because you are introducing voids or your nano material has a larger CTE than the matrix. Either fix it or search for new applications for the failure experiment. It might help to research the field and actually state your hypothesis before mindless randon thought experiments...Good luck

sure hehe

Depends on the application. If it's IC related than matching CTE of Si or comparable material is ideal so that material has CTE's on the low end

First: Use of CTE (linear coefficient) will not generate the proper equation of state. But if you use it then try this:[ (Aa-Ab) ]/[1-(EaC)/EbC)] intergrate between the low temperature and the Tg of the polymer matrix, then reset the intergration between Tg and Upper cure temp of the composite.

Where Aa is component A CTE

Where Ab is component B CTE

Where EaC is the modulus of component a times the cross-sectional area of A

Where EbC is the modulus of component b time the cross-sectional area of B.

Mind this is a simple free end length calculation. Also, note that all quanities are functions of temperature. Therefore, for best calc. use an expansion series.

Most of this can be found in Introduction to Polymer Physics, MIR press,

Also, if you like you can use the 3 dimensional calc. Remember the translation along the principle component axis.

There are a number of papers on this, one of the best was presented at NATAS conference in 1987. I don't have the citation in front of me. But will find it if you need. NATAS: North American Thermal Analysis Society.